Bituric acid and its homologues



Patented July 17, 1923.

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FRITZ QUADE, OF BERLIN, GERMANY.

PROCESS OF MANUFACTURING COMPOUNDS SOLUBLE IN WATER OF DIET-HYLBAR-BITURIC ACID AND ITS HOMOLOGUES. i

No Drawing.

To a]! when] it may concern lie it known that l, l ltl"l'7. lfl .lili. acitizen ot the Republic of Germany, residin s at Berlin. tlermany.-haveinvented certain new and useful Improvements in Process of Manutacturinc(ompounds Soluble in ater oi l)ltllll \'ll)tll'l)ltlll'lC Acid and itsllomologues. of which the tolltnvina is a specitication.

Diethyl-barbituric acid known as a opiate and its homol'ogues do not.possess any soothing etleets. To overcome slwplessncss', partly due tol'celings of discomfort it. is essential to take large doses of thisremedy which is not quite harmless to the human body. There is thereforea necessity to combine the diethyl-barbituric acid or the more easilyabsorbed and therefore more quickly acting sodium salt with soothing.pain sedative and if possible harmless products. Amongst these are thefirst to be considered the salts oi the acetylsalicylic acid which donot affect the stomach and are easily ab sorbed. i

It was,.however. toundthat a mixture of sodium (liethyl-barbiturate withsalts of the acetyl-salicylic acid sinters. separates acetic acid, andshows indications oi decomposition, obviously on account of theformation of the po sable sodium acetyl-salicylate.

This drawback may be obviated by using for the mixtures novel salts ofthe diethylbarbiturie acid which have not been ilescribed hitherto andare obtained with the alkali-earths. lhesc salts are such which can notbe formed easily as the sodium diethyl-lmrbiturate and also do notdecompose so easily,

It freshly precipitated calcium carbouate is treated with a solution ofthe dicthvl barbiturio acid no transform-ation takes lace, nor doescrystallized magnesium ca r- 415 lionate react with diethyl-barl)ituricacid. However, freshly precipitated magnesium carbonate. not yet incrystalline sta e reacts avith the diethyl-barbituric acid, but the so;lution thus formed decomposes when being 5 concentrattal by evaporationupon a waterbath. There is formed a dillicultly soluble product, whichalter the decomposition by mineral acids gives a diethyl--barbituriehygroscopic and easily deeom for instance during the concentra t9 tionby evaporation.

Application filed November 9, 1921. Serial No. 514,077.

acid which has a i'usin; point l'ar lower 1t. however, a solution oimagnesium d1ethyl-barblturate.. which has been obtained by intrmlm-ingtreshly pre.-ipitated magnesium carbonate. that has not yet assumed thecr \'stalline state, into a hot saturated solution ot diethyl-barbiturieacid purilied by filtration aml the mixture is thenconcentrated byevaporationnnder a vacuum. a salt with a little more than (1% ofmagnesium and tolerably easily soluble '65 in water is obtained. Toobtain a product which is soluble in water it is important that not.much more of the magnesium conipound is ei'nployed than corresponds tothe amount of magnesium to be expected in the final product; accordingto theory, viz, 5 .lJ i' /i. ill is also possible to manufacture thesalt from magnesium hydroxide. it the solution obtained is evaporatedunder a vacuum.

The soluble lime salt with 10% of Ca (theory 99%) .is obtained bydigesting a solution oi diethyl-liarbituric acid with calcium hydwxidewith the aid of heat, and. drying; the filtrate under a vacuum.

The new eartl1-all ali-salts ot the diethylbarbituric acid so obtained,are easily absorbed and aresoluble in water. They give durable mixtureswith the earth-alkali-salts oi the acetyl-salicyclic acid, among which35 those products that contained solely magnesium salts, give the mostsuitable tabloids.

Soluble salts may be obtained by means of the same process also fromhomologues 9 ol' the diethylbarbituric acid lor instance fromphenylethyl-barbituric acid.

ITLIIHI'I/l/K l l parts of the dicthyl-l'iarbituric acid are dissolvedby heating in the twelvet'old quantity of water and 30 parts '9(calculated in the dry state) of freshly precipitatedmagnesium-hydroxide are suspended in a little water and added gradinally. The solution which is tilt'cred oll' 'lrom a.sli;1'ht sediment. isconcentrated by evap- 1 0 oration and dried under a. vacuum atas low atemperature as possible.

Already at ordinary temperature one part ofthe salt dissolves in 30parts of water, but at the temperature of the human body 105 (37) thesolubility is considerably greater.

Having thus particularly described the nature. of my invention, What Iclaim as new and desire to secure by Letters Patent of the United Statesis:

1. Process of manufacturing water solu ble compounds ofdisubstitutedharbiturio earth metal compound and concentrating thefiltered solution by evaporation under a vacuum to dryness.

3. Process of manufacturing Water soluble' compounds of disubstftutedbarl'iituric acichwhich process consists in digesting a solution of thedieth lba-rhituric acid with tered solution by evaporation under a menum to dryness.

- 4. Process of manufacturing Water solu-f ble compounds ofdlsubstitutcd harbitui'ic acid, which process consists in digesting a"solution of the diethylbarbituric acid with the theoretical quantity ofmagnesium carbonate and concentrating the filtered solu -'tion h'e'vaporation under a vacuum to dryness. 1

. P rocess of manutacturing Water solw ole compomids oi? disubstitutedbarbituric acid, Tllfth process consists in digesting a solutie 'l ofthe diethylharbituric acid, with the theoretical quantity of a freshlypro cipitated magnesiumycarhonate and concentrating the filteredsolution by evaporation under a acuum to dryness.

6. As'new products the herein described water soluble alkali-earthmetaisal s of disuhstituted barbituric acid.

ture.

the theoretical quantity of an alkali earth metal compound andconcentrating the fil- FRITZ QUA DE.

In testimony whereof I my signa

